EXERTIONAL RHABDOMYOLYSIS. Jeffrey m mjaanes md, facsm

Transcription

1 EXERTIONAL RHABDOMYOLYSIS Jeffrey m mjaanes md, facsm

2 LEARNING OBJECTIVES By the end of this presentation, the learner should be able to: 1. Describe the pathophysiology, potential contributing factors and general clinical presentations of rhabdomyolysis 2. Summarize management paradigms for different degrees of acute rhabdomylolysis

3 DEFINITION Roots: rhabdomyo : skeletal muscle; lysis : breakdown, degradation Rhabdomyolysis = breakdown skeletal muscle with release into circulation of myocyte contents Myoglobin Creatine phosphokinase (CPK) Lactose dehydrogenase (LDH) Transminases (aspartate and alanine aminotransferase, AST and ALT) Spectrum Mild ßà Fulminate Treatment depends on degree, symptoms and signs

4 CAUSATIVE FACTORS EXTRINSIC Medications/toxins Stimulants (ie amphetamines) Antihistamines Ephedra Statins Alcohol Infection Exertional heat illness Dehydration Excessive muscle loading (ie eccentric) Especially if deconditioned and rapid acceleration in training

5 CAUSATIVE FACTORS INTRINSIC Sickle cell trait Genetic muscle diseases/enzyme deficiencies McArdle s (and other CHO ) Carnitine deficiency (and other lipid ) Metabolic conditions: Diabetes mellitus Hyperthyroidism Autoimmune conditions Polymyositis

6 Typical laboratory analyses CBC CMP AST, ALT, Ca, K, Po4 CPK LDH Uric Acid UA with microscopy: Hgb w/o rbc s; muddy casts Also, if indicated/severe: Coagulopathy panel: PT, PTT, fibrinogen, FSPs

7 DEGREES OF RHABDO ISOLATED MILD MODERATE SEVERE FULMINANT

8 ISOLATED MUSCLE GROUP Cause: Excessive loading of single muscle group (weightlifting) Symptoms: Mild soreness of affected muscle Labs: CPK may be mildly elevated (< 20,000 mg/l) Occasionally myoglobinuria Self-limited

9 MILD RHABDO Symptoms: Mild muscle soreness Resolves in 1-2 days Physical Exam(PE): Mild muscle soreness/tenderness No pain with passive muscle stretch Labs: Elevated CPK < 5,000 mg/l Typically ~ 3,000 Mild increase AST/ALT 2-3 times normal Peaks in 1-2 days

10 MILD Rhabdo: Treatment Treatment: PO rehydration Avoid strenuous exercise x 1-2 days May return day after becoming asymptomatic if labs improving Monitor for recurrence/worsening of symptoms Education re: preventive measures

11 MODERATE RHABDO Symptoms: Moderate muscle stiffness, soreness Physical Exam: Moderate muscle tenderness Moderate pain with passive stretch at end of range Labs: CPK Elevates in first few hours, peaks in 3-24 hrs Typically < 30,000 mg/l AST/ALT Peak within 1 day (3x normal) Cr ( mg/l) LDH

12 MODERATE Rhabdo: Treatment Treatment: IVF (typically 2L isotonic) & monitor If improves, PO fluids and re-evaluate in hrs If symptoms improved but labs unchanged, Consider further IVF, reassess every 4-6 hours, consider transfer to hospital If no improvement in symptoms or labs, or if myoglobinuria, Refer to hospital for continued IVF and monitoring

13 SEVERE RHABDO Symptoms: Severe muscle soreness Pain with any activity Exam: Tight, tender muscles Pain w/ passive stretch Limited range due to pain Labs: CPK (> 30,000 mg/l) Cr (> 2 mg/l) AST, ALT (increase to > 3x normal within 2-3 days) LDH (increases to 3x normal in 2-3 days) Uric acid Electrolyte changes: K, Ca Acidosis

14 SEVERE Rhabdo: Treatment Initial Treatment: IVF (2L bolus, then cc/h) Repeat labs every 3-4 hours If symptoms and labs improve, then PO hydration and observe If little change, Consider continued IVF, compartment tests, etc If worsening labs, Transfer to ICU, compartment pressure monitoring, electrolyte corrections If myoglobinuria, Continue IVF at cc/hr

15 FULMINANT RHABDO Symptoms: Severe muscle pain Severe weakness inability to walk Collapse Mental status changes: obtundation Heat stroke, dehydration, shock Symptoms may progressively worsen and be refractory to treatment Signs/ PE: Tense, tender muscles Extreme pain with any passive stretch Mental status changes

16 FULMINANT RHABDO LABS: CPK: > 50,000 mg/l AST, ALT, LDH Uric Acid Acidosis Persistent acidosis ominous sign Electrolyte changes: Initial: K, Ca, PO4 Later: May see K, Ca, PO4

17 FULMINANT RHABDO Causes of morbidity/ mortality: Acute compartment syndrome Muscle necrosis, amputation Renal failure Hepatic failure, multi-system organ failure, shock DIC Severe acidosis or electrolyte abnormalities Cardiac dysrhythmias TREATMENT: ICU Cardiac monitoring for dysrhythmias Aggressive IVF Monitor and correct electrolyte abnormalities Compartment pressure monitoring Ortho C/S for fasciotomy evaluation

18 FOLLOW UP/ RTP If uncomplicated mild-moderate rhabdo in healthy individual: May gradually resume activities Once asymptomatic CPK, LDH, AST, ALT declining to 50% peak value or near normal (3 days) Activity limited by symptoms (fatigue, muscle pain/tightness) Severe or fulminant rhabdo: Cautious RTP If recurrent bouts of rhabdo, or severe/fulminant: Need to r/o Myopathy (muscle biopsy) Muscle enzyme deficiency (muscle biopsy, etc) Underlying disease (thyroid panel, autoimmune work up, etc)

19 Conclusions: Key points Rhabdomyolysis is a spectrum Maintain high index of suspicion Key labs include CPK, transaminases, electrolytes Initial labs may be deceptively normal may rise over 3-48 hours Key to treatment is rehydration Low threshold for intensive care monitoring

20 THANK YOU BIBLIOGRAPHY: Armstrong L, Casa D, Millard-Stafford M, Moran D, Pyne S, Roberts W; Exertional heat illness during training and competition: ACSM Position Stand; Medicine & Science in Sports & Exercise; 2007 Asplund CA, O Connor FG; Challenging Return to Play Decisions: Heat Stroke, Exertional Rhabdomyolysis, and Exertional Collapse Associated With Sickle Cell Trait; Sports Health; 2016; 8(2) Herring S, et al; Selected Issues in Injury and Illness Prevention and the Team Physician: A Consensus Statement; Medicine & Science in Sports & Exercise; 2015 Sawka M, Burke L, Eicher R, Maughan R, Montain S and Stachenfeld N; Exercise and Fluid Replacement: ACSM Position Stand; Medicine & Science in Sports & Exercise; 2007 Scalco RS, et al; Exertional rhabdomyolysis: physiological response or manifestation of an underlying myopathy?; British Medical Journal; Open Sport Exercise Medicine. 2016; 7;2(1) Schleich K, Slayman T, West D, Smoot K.; Return to Play After Exertional Rhabdomyolysis; Journal of Athletic Training. 2016; 51(5)